Happy Rosh Hashanah—Not!

Iran's leaders aren't known for their love of Jews or Judaica. So it came as a surprise when on Wednesday the Islamic Republic's newly elected President Hassan Rouhani tweeted a Jewish New Year greeting from a Twitter account attributed to him. "As the sun is about to set here in #Tehran I wish all Jews, especially Iranian Jews, a blessed Rosh Hashanah," read the tweet.

Western journalists eager for signs of moderation in the Tehran regime were ecstatic. The liberal Israeli daily Ha'aretz saw in the message a...